Telephone cable



May 3, 1932.

W. K. WESTON TELEPHONE CABLE Filed Feb. 9, 1929 INVEN TOP W K. Wes 101vATTORNEY Patented May 3, 1932 UNITED STATES PATENT; oFFmE WILLIAM KIRBYWESTON,

OF SANDERSTEAD, SURREY, ENGLAND, ASSIGNOR TO WESTERN ELECTRIC COMPANY,INCORPORATED, OF YORK, N. Y., A CORPORA- 'IION OF NEW YORK TELEPHONECABLE Application filed February a, 1929, Serial No. 388,709,

In the manufacture of cables for telephone communication it is usual toselect certain conductors for particular circuits and to assemble theminto corresponding groups which may be pairs, quads or larger order mpedients are in groups. In such anarrangement proper balan'ce ofelectrical characteristics in each,

group is essential to high quality transmission and to attain suchbalance various exuse. It is also necessary to for distinguishing anyconductor, pair or sub-group from others in any particular group in thecable. T his is usually done by applying an identifying color or mark tothe paper insulation of the conductors.

The present invention provides an improved electric cable in which allthe insulated conductors of one group or in any individprovide a meansso ual group are marked or identified by the of either of the pairs.

same color or are marked sothat the coloring material both as regardsquality from an electrical standpoint, and quantity per unit area oneach conductor insulation, is as nearly as possible the same., By thismeans any electrical unbalance due to difierence of electricalcharacteristics of the coloring or marking of conductors in each groupmay be appreciably reduced.

The invention will be described by way of example with reference to aquadded cable as represented in the accompanying drawg The cablecomprises a plurality of quads 1 arranged in layers which are shieldedbv a metallic screen 2 in known manner. The quads each contain fourconductors insulated from each other by a paper insulation applied forexample in the form of a ribbon. The four conductors of each quad arearranged in pairs. The two conductors of each pair are twisted together..The number of twists per unit of length of one pair preferably difiersfrom that of the other pair in the same quad. The pairs are twistedtogether to form the quad and the length of lay of the quadded twist isdifferent from that Each conductor is in sulated by a paper ri bon of aneutral color or of a natural color printed with identificaand in GreatBritain February 14, 1928.

tion marks. The color or colors of the insulation employed for all theconductors in one quad are all the same. The four papers for one quadmay preferably be chosen from adjacent positions in the paper roll,these four papers being imprinted with the same amount of ink on eachpaper, the. ink being also of the same color or composition. Theidentification of either pair in any quad is permitted by usingdifferent markings on the pairs, taking care that in giving thisdifferent marking the same amount of coloring material is present on allthe conductors of the quad. This is shown in the figure in whichconductors A, B, form one pair, while conductors G, D form the otherpair of a quad 4:, The identification in this case may be, for example,by means of black marks upon a natural color ground and the conductorsC, D would have narrow stripes for identification purposes, but thetotal amount of color per unit of surface of any of the conductors, A,B, C or D is the same. If desired,'or' course, the conductors of eachpair may also be identified in a similar manner provided the saidprecaution is taken. The identification between the conductors ofdifierent quads may be made by using different colors for differentquads, for example quad 5 may comprise conductors which are insulated bymeans of paper having a red stripe on a natural colored round, theidentification between the pairs of quad 5 being permitted by arrangingdifferent width stripes on the insulation as in the case of quad 4.

By so marking the insulation of the conductors in the cable it is foundthat capacity unbalances are not introduced through nonuniformity of theinsulation surrounding the conductors of each quad, and in order furtherto ensure this it is preferable that the disposition of the ink uponeach of the papers of a quad is made substantially in similar manner forall four conductors in order that the qualities of the paper may not bedifferently afl'ected.

The identification marks shown in the drawing are in the form of stripesat right angles to the length of the conductors. This is obtained bymarking the ribbon with ferent angle oblique stripes so that afterwrapping around the conductor the angle of application of the ribbonproduces the right angle direction of the stripe. If desired the stripesmay be marked on the paper in such a way in the finished cable that theymay appear at a difon the insulation and in some cases a difi'erence inthe angle may be used for giving the identification between difierentconductors of a quad or between the conductors of different quads.

A lead sheath or the like 3 is provided in the usual manner to completethe cable.

In an actual cable the quads would be much closer then shown on thedrawing which is intended to illustrate the principles of the inventionwith most clearness.

It should be understood that it is within the scope of the invention toother insulating materials than aper as described above and that theinsulation, eve: case of paper, may be applied in other iorms than thatof a ribbon; coloring matter furthermore may be ap, lied to theinsulation alter the latter has been placed upon the (acnductor. Thus,the

conductor may be insulated with papier miich the identification colorapplied been formed the papiecmdch the conductor drier t is claimed isl; i i telephone c conductors, pap r i r a tors, a coloring substanceper insulation in such am its the capacities "fictive such formation asto sci, marks on said conduct A telephone cable a p pairs of conductors,paper insu conductors, coloring subs said paper in such amounts t o ofconductors of diiierand in such configur conductors may be ideir ledthereby, 8. A cable comprisin. nsulated conductors i aving colored identcation apto the outer surface of the aper wherein the ground color forthe marlicg the same for at least two oi the conduc ors in one group andthe identification ing is composed of such coloring matter and has suchconfiguration that said conductor" have substantially the samedielectric char acteristics and the markings on said con ductors aresubstantially difi'erent,

l. A cable comp-rising a plurality of paper insulated conductorsarranged in groups and having colored identification markings ap pliedto the insulating paper wherein for at least two of the conductors ofany one group the ground color for the marking is the same, and thecoloring matter 01 the marking is the same and is applied in the sameamount per unit area of paper insulation and wherein the coloring matterbeing the same for said 0011- ductors, the marking matter on the paperof one conductor of the pair being disposed differently from the markingmatter on the other conductor of said pair,

In witness whereof, I hereby subscribe my name this twenty-ninth dav ofJanuary,

WlliLlrlll/l lWESTOl-l,

